A power semiconductor device is used for a switching circuit and an inverter circuit for power control.
Although the power semiconductor device is required to have a high breakdown voltage and a high carrier mobility, the breakdown voltage and the carrier mobility of the power semiconductor device using silicon has reached the limit based on physical characteristics of Si.
In recent years, silicon carbide and nitride semiconductors, which have wider bandgap than Si, are expected to be used widely as materials of the power semiconductor device.
A vertical type semiconductor device using silicon carbide has a high breakdown voltage, but a carrier mobility thereof is lower than that of the semiconductor device using Si.
On the other hand, a lateral type semiconductor device having a heterojunction interface using a nitride semiconductor has a high carrier mobility exceeding that of Si, but there is a problem in that it is difficult to allow the lateral type semiconductor device to have a high breakdown voltage. Therefore, a power semiconductor device having both a high breakdown voltage and a high carrier mobility is desired.